No, your employer does not have to file an objection with the immigration department for you not to be allowed into Qatar. If you have had an RP that was cancelled/expired within the last two years, you MUST have an NOC to re-enter the country. It's not a question of whether or not you were banned, you will know that you can enter Qatar if you have your NOC in your hand at the airport. If you do not, you cannot.
Mandi